I have several NUC5i7RYH NUCs that periodically throw a BIOS POST error at startup and block waiting for user interaction. I am trying to suppress these errors or to at least get past them without requiring user interaction. The "Suppress alert messages at boot" option in the BIOS appears to be designed exactly for this scenario. For some reason, however, after enabling this BIOS option, my NUCs still wait for user interaction when they display a BIOS POST error. Are there any additional changes I need to make in the BIOS in order to get the behavior I desire?

Unfortunately, in my case, I cannot use the default BIOS values. The setup I have requires changes to the defaults that I listed in an earlier post in this thread. For instance, my bot partition requires legacy boot for the moment.

Here are a couple of updates since the last time.

First, it appears that the issue happens only when one of the USB devices enters a bad state during a previous Windows session. The devices that have caused the issue in my case appear to be USB speakerphones and webcams. Unplugging and re-plugging these devices appears to remove the problem because after that, the NUC can do a successful BIOS POST and then continue to load Windows. It appears that when these devices enter a certain bad state, they can cause the POST to fail.

Second, I have updated the BIOS to version 0358 on several of my NUCs and left version 0350 on others. Now, I am doing an A-B comparison to see if a BIOS update can successfully enforce the "Suppress Alert Messages at Boot" setting. So far it looks ok, but because the issue is difficult to reproduce, I need to let the test continue for much longer in order to be more certain that a BIOS update solves the problem.

I guess it is a bit clear, I am still not sure what the error message is but since you cannot load default settings, I would recommend you to unchecked USB from boot devices,Boot>Boot Configuration>Boot Devices>USBHope this helps.

One of my NUCs displayed a BIOS POST error today, so I was able to test whether or not disabling boot from USB devices in the BIOS helps. Unfortunately, it does not help. Specifically, with the USB device boot disabled in the BIOS, the BIOS POST error still appears. Therefore, I re-enabled booting from USB devices in the BIOS. Then, I proceeded to update the BIOS to the 0358 version. With the BIOS update, the NUC no longer displays the BIOS POST error.

I suggest that you try enabling the Fast Bootoption. If Fast Boot is enabled, the BIOS will not initialize the USB controllers at all - and thus should ignore the state of USB devices. This will, of course, result in the BIOS ignoring keypresses during boot; you will need to use the Windows 10 UEFI support for entering BIOS Setup (if you are actually using UEFI and Windows 10) or press and hold the power button for 3 seconds and get in through the recovery menu.